phosphor-hwmon failed to start with aspeed fantach sensor

[Patrick Venture]

On Thu, Nov 22, 2018 at 11:11 PM qianlihu <wangzhiqiang8906 at gmail.com> wrote:
>
> Hi all,
>
> On my board,when host powed off, the fan would stop.
>
> then,phosphor-hwmon failed to start
>
> debug:
>
> cat /sys/class/hwmon/hwmon0/fan1_input
>         read error Connection timedout.
>
> edit the config file,
>         LABEL_fan1 = fan1
>         REMOVERCS = 110 // 110 means ETIMEDOUT
>
> when host powerd on
>         1. echo add > /sys/class/hwmon/hwmon0/uevent
>         2. phosphor-hwmon started
>         3. host power off
>         4. phosphor-hwmon did not exit.
>         5. cpu usage of hwmon-read would be 4%
>
> when host powerd off
>         1. echo add > /sys/class/hwmon/hwmon0/uevent
>         2. failed to start phosphor-hwmon.
>
> I found when phosphor-hwmon init
>
>    Sensor::addValue would read fan1_input(there is no fan1_fault in sysfs),
>    and it caused read timedout unexpection.
>
>    so init failed.
>
> On my board,I  want to boot the bmc with phosphor-hwmon when host powered off.
>
> what should I do ?

You have a couple options, one will basically remove the sensor from
dbus on read failure, the other just leaves it but sets the value to
-errno (in this case ETIMEDOUT).

There are two configuration option switches for these, you can add it
to your bbappend:

EXTRA_OECONF_append = " --enable-remove-from-dbus-on-fail"

EXTRA_OECONF_append = " --enable-negative-errno-on-fail"

>
>
> Thanks
>
>
>
> --qianlihu